Johannesburg - Over 4 000 Satawu members employed by SA Airways (SAA) will strike on Thursday, the union said.
The airline had undermined wage negotiations, SA Transport and Allied Workers' Union (Satawu) spokesman Vincent Masoga said in a statement on Wednesday.
"This... recalcitrant management of SAA has unilaterally implemented their rejected initial offer of 6.23% of basic salary and all other benefits while the negotiations were still ongoing," he said.
He said that last week unions put the strike on hold after SAA offered a 6.5% increase across the board, with all benefits.
Workers were considering the latest offer when the airline implemented the rejected amount, he said.
SAA said it would comment on the matter later in the day.
Masoga said workers had reverted to their initial demand of an 8.33% increase in salary, housing allowance, medical aid, and meal allowance.
"It is rather appalling for publicly owned entities such as the SAA to treat workers in the most unequal and discriminative manner and in this case the SAA is guilty of preferential treatment of workers with more bias to the pilots."
He said SAA pilots had an "evergreen" agreement that awarded them a 15% increase and segregated hotel accommodation, as "pilots refuse to stay on the same floor with cabin crew".
"Our biggest concern is that this kind of a setup perpetuates racial inequalities as 98% of the SAA pilots are white and there seems to be no space at all for new entrants."